%0 Journal Article
%K lead
%K transmission electron microscopy
%K Health risks
%K iron compounds
%K bismuth compounds
%K Article
%K priority journal
%K Morphotropic phase boundaries
%K High resolution transmission electron microscopy
%K electric activity
%K bismuth
%K piezoelectricity
%K ferric oxide
%K nanoanalysis
%K Piezoelectric materials
%K In situ processing
%K Mechanical actuators
%K Piezoelectric actuators
%K Strain
%K Electric-field-induced strain
%K Field-induced strain
%K In-situ transmission electron microscopies
%K Lead-based materials
%K Lead-free piezoelectric materials
%K Mechanical response
%K Sensors and actuators
%K health hazard
%A J.X Zhang
%A B Xiang
%A Q He
%A J Seidel
%A R.J Zeches
%A P Yu
%A S.Y Yang
%A C.H Wang
%A Y.-H Chu
%A L.W Martin
%A A.M Minor
%A Ramamoorthy Ramesh
%B Nature Nanotechnology
%D 2011
%G eng
%I Nature Publishing Group
%P 98-102
%R 10.1038/nnano.2010.265
%T Large field-induced strains in a lead-free piezoelectric material
%V 6
%X Piezoelectric materials exhibit a mechanical response to electrical inputs, as well as an electrical response to mechanical inputs, which makes them useful in sensors and actuators1. Lead-based piezoelectrics demonstrate a large mechanical response, but they also pose a health risk2. The ferroelectric BiFeO3 is an attractive alternative because it is lead-free, and because strain can stabilize BiFeO3 phases with a structure that resembles a morphotropic phase boundary3. Here we report a reversible electric-field-induced strain of over 5% in BiFeO 3 films, together with a characterization of the origins of this effect. In situ transmission electron microscopy coupled with nanoscale electrical and mechanical probing shows that large strains result from moving the boundaries between tetragonal- and rhombohedral-like phases, which changes the phase stability of the mixture. These results demonstrate the potential of BiFeO3 as a substitute for lead-based materials in future piezoelectric applications. © 2011 Macmillan Publishers Limited. All rights reserved.